But few patients, and probably many doctors, have ever heard of another type - oxycholesterol.
And a new study by scientists in China show it may do the most heart damage of all.
It's long been known that a reaction between fats and oxygen produces oxycholesterol in the body. It comes through a process called oxidation.
Oxidation also occurs when foods tontaining fat are heated, such as in grilling meats, or frying chicken. Food manufacturers also produce oxycholesterol, in the form of trans-fatty acids and partially hydrogenated vegetable oils.
When oxycholesterol is added to food, it can improve texture, taste, and extend the shelf-life.
In the past, scientists have studied how oxycholesterol works on the cellular level, by damaging DNA. But this new study, by a team at the Chinese University of Hong Kong, is among the first to look at oxycholesterol's effect on other body functions, such as overall cholesterol.
In tests with hamster, those fed diets high in oxycholesterol had overall cholesterol levels 22 per cent higher than hamsters eating non-oxidized cholesterol.
The oxycholesterol group also had more - and larger - deposits of cholesterol in the linings of their arteries.
Those deposits raise the risk for heart attacks and strokes.
Oxidized cholesterol also decreases the elasticity of the arteries, which the body needs to respond to stresses, such as exercise or consumption of high-fat foods.
Scientists do not yet know whether anti-cholesterol drugs called statins will lower oxycholesterol.
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